If you had to pick one element as the most versatile, carbon would be it. We are carbon-based life forms in just about every sense of the word. In fact, "organic molecules" are basically defined as those built out of carbon, so inseparable is carbon from the workings of life as we know it. The hydrogen-eating bacteria thought to live miles down in the earth's crust, the bacteria that may live under thousands of meters of ice in Lake Vostok, even the most exotic sulfur-eating bacteria that live in thermal vents at the bottom of the ocean, all are built on a completely carbon-based foundation. Finding extraterrestrial life, say on Europa or maybe in a flying saucer on the White House lawn, would be no great surprise. Finding out it's not carbon-based would be a very big surprise indeed.

But life is just one of carbon's tricks. In pure form carbon can be anything from soft, slippery graphite to the hardest substance known, diamond. The difference between diamond and graphite is just in how the atoms of carbon are bonded to each other: In sheets that can slide around or in a locked three-dimensional matrix.

Graphite is very useful as a refractory material for high temperature crucibles and electrodes, and graphite fiber is used as a reinforcing material embedded in epoxy or other resins. Such composite materials are used in military airplanes, surf boards, and golf club shafts.

Diamond, because it has historically been kept expensive by the DeBeers cartel, has not found many uses outside of jewelry. Small manufactured diamonds are used as abrasives, but even they are a bit expensive. In the summer of 2003, however, we witnessed what is very probably the beginning of the age of cheap, large synthetic diamonds, with two companies, Apollo Diamonds and Gemesis entering the gem market with manufactured white and yellow diamonds respectively. Since diamonds are in fact dirt common even in natural form, and since they are really not very pretty as gemstones go, their value may well utterly collapse over the the next decade or two. The idea that they are valuable is, after all, a pure invention on the part of DeBeers, and as such it's unlikely to survive changing conditions.

Anthracite coal.
I purchased about 1000 pounds in the early 1990s for blacksmithing use by Jim Zimmerman at our farm. We had to build a special box on the trailer to bring it home, and most of it is still sitting in large plastic containers in the shed. No problem finding a sample for the table!
The sound is steel plate being beaten with a blacksmith's hammer after heating in a coal fire.Source:Coal DealerContributor:Theodore GrayAcquired:15 April, 2002Price: $0.008/ounce ($250/ton)Size: 2"Purity: >85%

Graphite rod from lantern battery.
I took apart one of those big lantern batteries probably some time in the late 1970s because I needed a graphite rod for stirring molten metals. Graphite is good because metal doesn't stick to it, it doesn't contaminate the metal, and it retards oxidation to some extent. In order to show you how it's done, I took apart another one in the summer of 2002 and photographed the process.

Click on the story book icon for this sample to see how to extract graphic from batteries. See below for another source of carbon rods.

Pyrolytic graphite.
Ed reports: The source (and inspiration) was this page about magnetism. The details for making pyrolytic graphite are on the site. The main point of these samples is that they have the highest diamagnetic effect of any material (the degree to which it will repel a magnet). The diamagnetic effect is strong enough that a piece of pyrolytic graphite will levitate over neodymium magnets, as you can see in the video. Source:Science ToysContributor:Ed Pegg JrAcquired:15 April, 2002Price: $2Size: 1"Purity: >99%

Titanic coal.
This is actual genuine totally certified in triplicate authentic coal recovered from the RMS Titanic on the bottom of the ocean. At least so says the certificate of authenticity:

Of course, if you read it more carefully, it doesn't actually say where the coal was recovered from, only that it was recovered during this expedition. It doesn't say whether the expedition took a detour to western Pennsylvania on their way to the bottom of the ocean.

But it's probably real: The company is real, and they really did salvage many objects from the Titanic. Here's an article about how tasteless the whole thing is. After reading that, if you still want to order some, you can: www.titanic-online.com.

The certificate says Jane Billman on it because this was a present for my wife, who is a Titanic fan. When I found it covered in dust at the back of a closet, I decided that the heavy responsibility of being a conservator of a genuine Titanic object should pass to the Periodic Table Table.

Sample from the RGB Set.
The Red Green and Blue company in England sells a very nice element collection in several versions. Max Whitby, the director of the company, very kindly donated a complete set to the periodic table table.

Sample from the Everest Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (except gases) weigh about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.

Graphite welding rods.
I didn't realize until just now that you could buy such perfect graphite rods very cheaply anywhere welding supplies are sold. They cost about a dollar each for 12" rods, and would be perfect for stirring molten metals if not for the copper cladding. It would be possible to melt the copper off, but I'm going to investigate whether some welding shops might carry ones without the copper.Source:Farm & FleetContributor:Theodore GrayAcquired:26 March, 2003Price: $4Size: 12"Purity: >98%

Salvaged block.
This block came from the now closed Anglo Great Lakes Corporation, Newburn Haugh, Newcastle-upon-Tyne, England, which used to make high-purity graphite for the nuclear industry, according to the source, Christopher Bell. He "recovered" this block from the grounds after the factory was closed. I have another larger block of graphite, which I've cut some pieces off of, and which I intend to cut up and use for making casting pots, molds, and the like. But this historical artifact will remain untouched as part of the collection. Here is the story of its recovery:

My coming across the graphite was purely a coincidence. I had set out to Newburn Haugh (a large area of low lying land in a large loop of the River Tyne- in fact "haugh" is old Anglo Saxon meaning flat or marshy land near a river) to explore the old Stella Power station site which was nearby the graphite works. After satisfying my curiosity at the Power station site I followed the river edge to the graphite works site (I didn't know it had been a graphite works at the time).
It was not long before I figured it out as there were numerous chunks of graphite simply lying around, generally of the size I enclosed, but some larger and some molded into shapes like screws and hollow cylinders. There were also large electrode pieces with a shiny, glassy finish - these don't leave a mark on paper.
After several trips I collected around 20kg of the material in total, why? I don't really know I just liked the look of them! Since then (1998/99) the site has been prepared for a large new Business Park and I imagine many other pieces of the graphite probably ended up in the in fill or crushed.

Nanotubes.
For centuries, people knew pure carbon in two forms, diamond and graphite. Diamond is three-dimensional matrix of carbon atoms in which each atom is bonded to four others in a tetrahedral arrangement. Graphite on the other hand consists of two-dimension sheets of hexagons, like a honeycomb, in which each carbon atom is bonded to three others. These sheets are loosely stacked on top of each other in bulk graphite, and it is their ability to slip around on each other that makes graphite so soft and slippery.

There's only one way to arrange the atoms in diamond, but it turns out that sheets of graphite can be wrapped around into tubes and spheres in a great variety of ways, forming some truly remarkable substances, some of which may turn out to be of vast importance.

The first really amazing form of carbon to be discovered is called buckminsterfullerene, after Buckmister Fuller the inventor and popularizer of many geodesic dome structures. Buckmisterfullerene is often referred to as "bucky balls" because it consists of molecules of 60 atoms in a graphite-like arrangement, curved and joined to itself to form a beautiful geodesic sphere.

These nanotubes consist of sheets of graphite rolled into tubes only a few nanometers in diameter. Nanotubes can be made in different diameters, and with one, two, three, or more concentric layers of wall. These happen to be multi-wall nanotubes.

What can you do with nanotubes? Well, one thing you can do, a trick the University of Illinois is famous for, is fill them with bucky balls, forming a sort of nano-peapod. Other things you might be able to do is build electronic circuitry with wires of unimaginable fineness. The tubes are also extremely strong: If you could make them long and bundle them into a substantial fiber, you could make threads and cables of extreme strength.

How are these incredibly fine, structured molecules manufactured? Is it some clever chemical synthesis in which atoms are assembled in an orderly way? Well, not exactly. The manufacturing process for bucky balls and nanotubes alike can be described basically as creating soot by burning or heating carbon and carbon compounds in high-temperature electric arcs, blasting with lasers, or some other similarly crude method. After making a bag of soot, you use various chemical methods to separate out and purify the particular form you're looking for. The trick is to adjust the conditions of your arc or laser in such a way as to maximize the percentage of the carbon that arranges itself into the form you want. For example, if you want nanotubes, you pass a laminar flow of gas through the arc. It's not too surprising that this encourages the carbon to form into tubes rather than balls: Think soap bubbles made by holding
the ring in a strong, steady breeze.

Nanotube powder is incredibly light and fluffy! This sample is a pile about half an inch wide the way it's stacked in the photo, but it weighs only about 7mg (0.007 grams). A full liter of this stuff would weight only about 25 grams, 40 times less dense than water.

Note that this stuff is extremely black. Really, really black. It looks gray in the pictures, but that's because I increased the exposure time to allow you to see the details of the structure, and I'm using very concentrated lights to put as much light as possible right on the sample. And needless to say, if you think you see some kind of tube-like thing in there, it's not a nanotube! The tubes typically range in length from tens to hundreds of micrometers, and may reach as long as a millimeter, but even such an extraordinarily long one could not be seen in anything other than an electron microscope, because they are so incredibly thin.

Diamond powder.
Looks kind of like graphite powder, doesn't it? This is very fine (0-1/4 micron) diamond powder intended to be used as an abrasive, and it really looks nothing like a bunch of tiny diamonds.Source:eBay seller reginaldvanceContributor:Theodore GrayAcquired:1 September, 2003Price: $50Size: 1"Purity: >99%Sample Group:Powders

Really big lumps of coal.
This massive piece of sculpture is eleven dollars worth of eastern Kentucky's finest big block anthracite coal. It weighs a bit over 200 pounds and as I write this my back is telling me I should have asked for help lifting it up onto the stack of two NeXT cubes it's sitting on. (NeXT cubes make good display stands for all sorts of things, and since they are made of magnesium, they are especially appropriate in an element collection.)
People say you can find fossils in coal, but I haven't seen any in these blocks. Unless of course you count the fact that the whole thing is one big fossil, hence the term fossil fuel.Source:Coal DealerContributor:Theodore GrayAcquired:24 November, 2003Price: $11Size: 30"Purity: >85%

Beautiful varnished coal.
These are varnished lumps of eastern Kentucky anthracite coal (see above sample for a couple of bigger lumps). While I was picking these out at the coal yard in late November I thought about joking with the coal dealer that I was doing my Christmas shopping, but then I decided that he'd probably heard enough "lump of coal for Christmas" jokes in his life, so I kept my mouth shut. Personally I wouldn't mind getting such a beautiful lump of stuff as a present, and my kids greatly enjoy varnishing and/or smashing it too. The phrase of course comes from a time and place where many people heated with coal and had great bins of it in their basement: Familiarity breeds contempt and all.Source:Coal DealerContributor:Theodore GrayAcquired:24 November, 2003Text Updated:20 November, 2008Price: $0.05/poundSize: 30"Purity: >85%

Huge slabs of pyrolytic graphite.
These massive slabs of pure pyrolytic graphic must have cost someone (Martin-Marietta according to the label) a pretty penny ($200 each in 1990, according to the seller). Pyrolytic graphic is the same as regular graphite (sheets of hexagonally bonded carbon atoms), but in pyrolytic graphite the sheets are all arranged in the same direction, in a flat pancake. In normal graphite there are zones of order like that, but as a whole the orientation of the sheets is random, making ordinary graphite an isotropic material. Pyrolytic graphite on the other hand has a definite directionality to it, with, for example, widely different diamagnetism in the direction of the sheets v.s. perpendicular to them. It can also be cleaved into thinner and thinner layers like slate or mica.Source: rmbidwellContributor:Theodore GrayAcquired:21 November, 2003Price: $50/2Size: 10"Purity: >99.9%

Carbon-filament lamp.
The story of Edison slaving away trying one kind of filament after another until he finally hit on one that would burn long enough to be practical is a classic story of cleverness and hard work. And this is an example of the kind of lamp he came up with, the carbon filament incandescent bulb. Compared to modern tungsten filament bulbs these were dim, inefficient, and short-lived bulbs that burned so hot they tended to set things are fire. Compared to candles, oil lanterns and gas lights, they were bright, efficient, clean bulbs that were much less likely to set anything on fire. It's all relative. And of course modern tungsten filament bulbs are horribly dingy and inefficient compared to fluorescent or LED bulbs.
The filament in this bulb looks shiny, almost like wire. The bulb expert it's from explains:

The large tipless carbon is a bulb made in the late teens [1910's] as the carbon was nearly at the end of its life cycle and having reached its greatest efficiency point before being replaced forever by tungsten. This was the "improved" carbon or "metalized" carbon which was a graphite paste baked over the carbon core.

Graphite lubricant.
I've generated huge amounts of powdered graphite while machining blocks of graphite to make molds for thermite casting, so I found it humorous to buy a little bit more in a tube. But it really is a very good lubricant: After doing the graphite machining all my tools run nice and smooth, and even my floor is extra-slippery. The stuff gets everywhere.Source:Hardware StoreContributor:Theodore GrayAcquired:20 November, 2003Price: $3Size: 5"Purity: >90%Sample Group:Powders

Congo cube diamond.
Congo cubes are really strange objects: pure natural diamond crystal, yet astronomically less expensive than diamonds normally are. (As this was a very generous Christmas present I'm not going to go on and on about how cheap Congo Cubes are, and one this large is actually not all that cheap in an absolute sense, it's just a lot less than the many thousands that a comparable 3 caret single-crystal diamond would cost.)
They come in a wide range of sizes and shapes, but most of them are fairly cubical, which raises the question: Why cubes? The individual crystals that make up a Congo Cube are randomly oriented, so why should the thing as a whole assume a cube shape? I have no idea. It would also be interesting to find out what's inside: Is it dense or are there air gaps or inclusions of dirt? What would it look like if you polished one face of the cube?
Want to find our for yourself? Look up Congo Cubes in google or eBay you'll find all sorts available.Source:Chris CarlsonContributor:Chris CarlsonAcquired:25 December, 2003Price: DonatedSize: 0.2"Purity: >90%

Copper-graphite block.
I have copper and I have graphite, but this mixture is not like either. I wonder if it would make a good mold material, but I don't have enough to experiment with. The source has the following to say about it:

Copper graphite, This sells well on ebay, think this is used for motor brushes, about the strangest stuff I have ever seen, you'll have NO trouble convincing people it is some weird Roswell metal. Interesting thing you can do with it is cut out a narrowish bar of it place in a "quarter shrinker" and once zapped with enough juice makes about the most tough material i have EVER, come across! It is like something out of science fiction after that treatment. It can be pounded and beaten on an anvil like wrought iron when hot, but good tool steel, tungsten carbide drills, lasers, ceramic lathe bits and other means of parting it don't cut it until it is heated enough to almost melt/burn! Silicon carbide cut off wheels will grind is slooooly though.

Stock offering commemorative.
I got a funny email one day.... A man in New York City wondering whether I knew where he could get a few pieces of anthracite coal on short notice. Seems he had sent similar emails to several people he found through a google search on coal and I was the first sucker to respond. I considered telling him about the news story I had read recently about the last New York City public elementary school still being heated with coal in the third millennium, but instead I offered to mail him a box of blacksmith's coal, seeing as how I have a ton (by which I mean 2000 pounds) of it at the farm.
In exchange he sent me this lovely block of cast acrylic, a test piece for a trinket meant to commemorate the issuance of stock on behalf of a company named Anthracite Capital, Inc.. How cute. Later, before he had finished these blocks, I went back to the coal yard and picked up some much nicer-looking coal samples (see above) but he refused all offers to replace his lousy Pennsylvania chunk with shiny Kentucky block.
Don't you think a company called Anthracite Capital, Inc needs a huge coal sculpture in their front lobby? I sure do.Source:Executive CreationsContributor:Executive CreationsAcquired:15 December, 2003Text Updated:11 August, 2007Price: DonatedSize: 4"Purity: 85%

Carbon fiber cloth.
Graphite (carbon) fibers are very strong, much stronger than things like nylon or other typical thread materials. For this reason carbon fiber is often used as a reinforcing mechanism in composite materials. Typically some kind of resin binder, like epoxy, is impregnated into the cloth, which is then wrapped around or over a form to give it the desired shape. When the resin hardens the result is a stiff, extremely strong shell that gets most of its strength from the fibers, not the resin. This kind of material is used to build airplanes, bicycle frames, even high-pressure gas cylinders for scuba diving.

Or so I thought: Reader Jason Dostal has corrected this last sentence as follows:

I do have one small correction for you though on your carbon page. You mention that carbon fiber is used in the construction of high pressure gas cylinders used for scuba diving. That is partially true - they do construct fiber-wrapped high pressure gas cylinders, but we don't use them for scuba diving. I have several small (68 cubic inch, 3000PSI) tanks that I attach to my paintball gun, because they are very, very light. Firefighters also use fiber-wrapped SCBA (Self Contained Breathing Apparatus) tanks due to their lightweight. And that is exactly why divers do not use them. The tanks are too light for diving. The materials they are made out of do not give the cylinder enough negative buoyancy to offset the buoyancy created by it's water displacement. You would have to wear a huge amount of lead to offset the natural buoyancy of the tank. We don't even really like aluminum tanks - the little 80 cubic foot aluminum tanks are kind of looked down upon by us "serious" divers, as they have poor buoyancy characteristics - they just get too light underwater. We do use aluminum cylinders to carry additional gases with us when doing decompression diving, but for the most part we use good, heavy low pressure (2400/2650 PSI) steel 104 cubic foot tanks (or other capacity).

Native graphite.
I'd really love a piece of native graphite from the Borrowdale mine in England, where graphite was first discovered (creating the modern pencil industry), but failing that, this will have to do. It's native graphite from New Jersey.Source:Franklin Mineral MuseumContributor:Theodore GrayAcquired:6 August, 2004Price: $6Size: 2"Purity: >95%

Hand-made pencils.
In April, 2004 I wrote about making pencils by hand in my Popular Science column. Here's a picture showing all the stages from graphite to final pencils: See the article (available online) for more details.Source:Theodore GrayContributor:Theodore GrayAcquired:15 April, 2004Price: DonatedSize: 7"Purity: >95%

Industrial Diamonds.
These pretty little yellow diamonds are entirely synthetic. They are pretty small, not quite a powder, but not exactly something you could make a ring out of. It looks like synthetic diamond technology is making good progress, however, and it might not be too long before you can buy fistfuls of large gem grade diamond for a few dollars. It's about time, I say, people are spending way too much money on boring clear stones.Source:Ivan TimokhinContributor:Ivan TimokhinAcquired:28 December, 2006Text Updated:7 January, 2007Price: DonatedSize: .01"Purity: >99%

Vacuum tube with graphite.
This seems to be an amplifier tube of some sort, why it has graphite electrodes I don't know. The same source sent me another tube that contains loose beads of mercury, another thing you don't commonly see in vacuum tubes. Not that you commonly see vacuum tubes of any sort these days.Source: Max CaneContributor: Max CaneAcquired:3 September, 2007Text Updated:3 September, 2007Price: DonatedSize: 5"Purity: >90%

Graphite mold for making tungsten carbide.
This is a little graphite mold I made for a Popular Science column about making tungsten carbide bits from scratch. Well actually, from tungsten carbide and cobalt powders. It turns out this is surprisingly easy, though the quality of the resulting bits can't possibly match that of commercially created material.
The edges of the mold are thinned because it spent minutes on end directly under an oxyacetylene flame being heated to around 6000F. Frankly it's a testament to the temperature and oxidation resistance of graphite that there's anything left at all.
Look under tungsten to find the actual bits I made.Source:Theodore GrayContributor:Theodore GrayAcquired:1 December, 2008Text Updated:29 January, 2009Price: $0.50Size: 1"Purity: >98%

Diamond grinding wheel.
Very attractive diamond-studded grinding wheel. The industrial-grade diamonds are embedded in a matrix of relatively soft iron, I'm pretty sure the bronze color is a plating, but it's too pretty to use and find out.
The gaps are to allow the chips to escape, and possibly for cooling as well.Source:Harbor Freight Tool CompanyContributor:Theodore GrayAcquired:11 March, 2009Text Updated:12 March, 2009Price: $25Size: 5"Purity: <2%

Borrowdale graphite.
The mine at Borrowdale was the first, and for a century the only, source of graphite, making it critical to the world's supply of pencils in the 1700s.Source:Andrew GoodallContributor:Andrew GoodallAcquired:2 April, 2009Text Updated:3 April, 2009Price: DonatedSize: 2"Purity: >95%

Copper-clad welding carbons.
Common copper-clad graphic rods used in welding. The copper is more electrically conductive than graphite, preventing excess voltage drop if the electrode clamps are attached at the far end of the rods. As the rod is consume the copper is vaporized a bit back from the end.Source:Farm & FleetContributor:Theodore GrayAcquired:16 April, 2009Text Updated:17 April, 2009Price: $5Size: 0.25"Purity: >95%

Low-grade diamond.
This is a low-grade 2.71ct natural diamond. It's quite large as diamonds go, but only semi-transparent and therefore worth astronomically less than you might think: Only about $100. It's also no longer of this world, because I burned it up during shooting for my Popular Science article about how to burn up diamonds.Source:eBay seller emerald-importsContributor:Theodore GrayAcquired:28 June, 2009Text Updated:29 June, 2009Price: $100Size: 0.25"Purity: >98%

Very large Congo cube diamond.
This was a huge, HUGE 7.45ct diamond before it exploded. "Congo Cube" diamonds are clusters of small yellowish crystals. They are worth far less than clear gem-quality diamonds, but one this big is still several hundred dollars.
When I say "exploded" I mean it seriously exploded, in fact with such force that two diamond fragments dug holes into the lens we were using to photograph the event. It wasn't supposed to explode. I was heating it with an oxy-hydrogen torch to get it to catch fire and burn (for my Popular Science article about how to burn diamonds) when suddenly and without warning there was a tremendous SNAP, I felt something hit my hand hard, and we all simultaneously realized that this was a very expensive SNAP.
There must have been some kind of internal fracture that gave way as it reached yellow heat. We had successfully burned a smaller Congo Cube diamond and a low-grade regular diamond without incident, but this one was much bigger and thus more susceptible to uneven heating, I suppose.
Fortunately we were able to gather a few of the fragments and use them in subsequent photography runs, including showing how they burn in liquid oxygen.Source:eBay seller sherl111Contributor:Theodore GrayAcquired:28 June, 2009Text Updated:29 June, 2009Price: $280Size: 0.3"Purity: >98%

Chrissy Caviar.Chrissy Caviar is just like regular caviar, except instead of being fish eggs, it's human eggs. More specifically, it's Chrissy's eggs. Needless to say, Chrissy is an artist.
Sadly this pen is does not contain any actual Chrissy Caviar, it's just a commemorative item. The real thing is packaged in glass jars and displayed in a deli case at whatever museum it is at (which changes from time to time).Source: Chrissy CaviarContributor:Theodore GrayAcquired:16 October, 2009Text Updated:26 October, 2009Price: $20Size: 6"Purity: 80%

Amber with bugs.
I picked this piece of amber out of literally thousands available at a big fossil show because it was really big, really cheap, and it had bugs in it. It's important to have bugs in your amber if you want to extract DNA and recreate dinosaurs, or impress the kids. I'm told that given the low cost this is probably "copal", not true amber, but hey, it's got bugs in it. Copal is much younger, only a few thousand years rather than potentially millions of years.

And it does have some really great bugs! Here's a close-up of one, which is about 1/4 inch in overall size:

I don't really know what the chemical composition of amber/copal is, but it's an organic resin which means it must contain carbon and hydrogen, and I figure it probably contains at least some oxygen, so I've listed it as being composed of those three elements, with carbon being the dominant one. Feel free to correct me if you know better.

In preparation for my coffee table book The Elements, I had my assistant Nick re-photograph this sample to my new, higher standards. Naturally it fell of the stand and broke into several pieces, which you can see here:

Silicon Carbide crystal.
The seller swears on a stack of bibles that this is natural (native) bismuth dug out of the ground in this form from the old Trajos silver mine in Chihuahua, Mexico. Unfortunately, this is not the case. The bluish cast does look very much like the film that forms on high-purity bismuth when it is molten, which may explain the sellers honestly mistaken identification. But this crystal is actually silicon carbide, possibly formed in an iron cupola from a reaction between the coke used to melt the iron and the silica fire brick lining the cupola. Because of the insistence of the seller that it was bismuth I made an effort to be absolutely sure about the identification, which was achieved by an SEM-EDS (Scanning Electron Microscope coupled to an Energy Dispersive X-ray Spectrometer) at the Center for Microanalysis of Materials, University of Illinois (partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439). The instrument allows one to measure the elemental composition of individual microscopic areas of a sample, in this case the cross section of single dendrite broken off the crystal. It showed a ratio of silicon and carbon consistent with silicon carbide on the inside of the dendrite, with a small component of oxygen found on the surface (and no doubt responsible for the bluish film).
Although this very sophisticated instrument allowed a definitive determination of what the crystal actually is, verifying that it is not bismuth requires no special tools: It doesn't melt. Native bismuth in this form would have been quite remarkable, as no such material is known to exist. But the fact that it's not bismuth in no way detracts from the fact that it's very attractive! It is one of the more beautiful crystals in my collection, and I really could care less where it's from.Source:eBay seller 4jdkContributor:Theodore GrayAcquired:28 January, 2004Price: $95Size: 4"Composition:SiC

Silicon Carbide crystal.
This is another silicon carbide crystal sold on eBay as bismuth. I'm not sure why people think it's bismuth or sell it as such. The physical properties are really completely different. But anyway, it's a very pretty crystal, man-made no doubt, probably as industrial waste from iron foundry work (silicon carbide forms in iron cupolas in a reaction between coke and silica firebricks). This one is from China and came with a lovely lacquered wood stand.Source:eBay seller birago123456Contributor:Theodore GrayAcquired:20 February, 2004Price: $88Size: 8"Composition:SiC

Baby rattle.
Some things you don't expect to see again. This is a baby rattle that I cut on an improvised lathe in my grandfather's workshop in his cabin in the Swiss alps over 20 years ago. I've though about it regularly ever since, and it never occurred to me, not once, not in the vaguest sense, that I would ever lay eyes on it again.Source:Theodore GrayContributor:Theodore GrayAcquired:20 January, 2007Text Updated:10 February, 2007Price: PricelessSize: 6"Composition:C(H2O)

Historical graphite.
This (hopefully!) is a genuine chunk of graphite from the nuclear reactor that housed the first sustained nuclear chain reaction ever created by the hand of man, on December 2nd, 1942 under the squash courts at the University of Chicago.
Reader Stephen Key, a dealer in historical radioactive artifacts, sends this confirmation of the item: "I can assure you that it is indeed genuine. I have the same one, except on mine one of the long sides it has "Argonne National Laboratory" printed on it. Later I saw the same exact item being sold on eBay, but this one came with
the original box and label describing the item and signed by the "Dean". It was mentioned these were made to commemorate or celebrate the 25th anniversary of the event."Source:eBay seller mrmavicaContributor:Theodore GrayAcquired:20 January, 2007Text Updated:8 April, 2008Price: $500Size: 4"Composition:C

Rubber penguin from Oliver Sacks.
This little rubber penguin was given to my daughter by Oliver Sacks to keep her entertained during a visit in 2003. Here's a picture of them from his 70th birthday bash:
It's not really an element sample, I just wanted a place to post that picture.
Shockingly, I had this sample cataloged as a duck for years until reader Robert Anderson's eleven year old son pointed out the error. Just goes to show you should never believe anything you read on the internet.Source:Oliver SacksContributor:Oliver SacksAcquired:8 July, 2003Text Updated:21 November, 2007Price: DonatedSize: 4"Composition:CHO

Invar block.
Invar is an alloy of primarily iron (64%) and nickel (36%), known for is unusually low coefficient of thermal expansion. This makes it useful for precision instruments and measuring devices that should as much as possible remain the same size and shape at all times. This block would be excellent for smashing such a precision instrument into a tangle mess of broken gears and dials. It weighs about 13 pounds and appears to have been roughly cut with a large band saw.Source:eBay seller boss1Contributor:Theodore GrayAcquired:19 June, 2007Text Updated:20 June, 2007Price: $60Size: 10"Composition:FeNiCCr

Fly.
This sample exists basically because my assistant Nick was borrowing a new camera, a Canon 40D, and needed something to do a test rotation of. Apparently a dead fly was to hand, so rather than work on our backlog of samples waiting to be photographed, he decided to spend half an hour photographing it.
The 360 spin video of this is really quite nice: You can see a lot of macro photographs of insects, but how many macro-rotations have you seen lately? Other than on this website, they are few and far between. The detail is pretty amazing: This shot was taking with a 10 megapixel Canon 40D using a Canon 65mm 1X-5X super macro lens, one of the finest available for objects down to about 1/4" across. And we've got 359 more of them, each as sharp and detailed as this one, just from different angles.Source:Nick MannContributor:Nick MannAcquired:27 October, 2007Text Updated:28 October, 2007Price: DonatedSize: 0.25"Composition:C(H2O)

Island In A Bottle.
This lovely, tiny little island scene came from a little shop in New Harmony, Indiana, a former utopian community that turned to tourism after failing at the utopia business. Being made of glass, wood, and various other organic materials, it contains silicon, carbon, oxygen, and hydrogen, plus some minor elements in the pigments.Source: New HarmonyContributor:Theodore GrayAcquired:2 December, 2007Text Updated:3 December, 2007Price: $15Size: 2"Composition:SiO2+C(H2O)

Electromagnetic Sensor.
Ah, this brings back memories. I made this thing some time in high school: It's supposed to be a general purpose "microphone" for electric or magnetic fields or vibrating metal parts. I turned the handle on a little toy wood lathe, and got a coil of fine wire from a small electric motor. Behind the coil are a couple of permanent magnets from Radio Shack. If you connect it (using the RCA jack at the base of the handle) to an audio amplifier you can actually hear things when you hold it near something that's producing oscillating fields (e.g. a speaker, electric appliance, etc). The idea behind the permanent magnets is to make it work with any vibrating metal, not just electrically-active objects, but that part never really worked as well as I'd hoped.Source:Theodore GrayContributor:Theodore GrayAcquired:23 December, 2007Text Updated:23 December, 2007Price: PricelessSize: 5"Composition:CuFe+C(H2O)

Custom Elemental Hexagon Cards.
This is a lovely little deck of Elemental Hexagon Cards. They are intended for divination purposes similar to the way you would use Tarot cards. A skilled and sensitive interpreter can tell you a lot about yourself using a deck of cards. Or a box of tea leaves or an old rubber tire, so why not element cards? They are pretty and inventive: This is a "custom" deck, meaning you get to choose the color and backgrounds. See the next sample for the mass-produced version. You can get them here.Source:CalyxaContributor:Theodore GrayAcquired:8 March, 2008Text Updated:8 March, 2008Price: $45Size: 3"Composition:CHO

Elemental Hexagon Cards.
This is a lovely little deck of Elemental Hexagon Cards. They are intended for divination purposes similar to the way you would use Tarot cards. A skilled and sensitive interpreter can tell you a lot about yourself using a deck of cards. Or a box of tea leaves or an old rubber tire, so why not element cards? They are pretty and inventive: This is a mass-produced version printed on standard playing card paper. See the previous sample for a custom-printed version. You can get them here.Source:CalyxaContributor:Theodore GrayAcquired:8 March, 2008Text Updated:8 March, 2008Price: $30Size: 3"Composition:CHO

Fancy chocolate tin.
This chocolate tin is a sign of the beginning of the end of good chocolate. It's a tin of Hershey's dark chocolate advertised as 65% cocoa. Promoting chocolate on the basis of its percentage of cocoa is an increasingly common marketing tactic, marred only by the fact that beyond about 50% more cocoa means worse chocolate. 99% chocolate, which is actually available, is basically impossible to eat.
The force at work here is snobbery, and the need for something that tastes really bad to base the snobbery on. (Things that actually taste good are of no use to snobs, because anyone can appreciate them.)
The same force is responsible for vast amounts of perfectly good grape juice being allowed to go sour and become wine. Basically, when you get right down to it, wine does not taste very good. But you can't show off how sophisticated you are by appreciating fine grape juice because pretty much everyone likes it. It tastes good. Wine, on the other hand, tastes bad, so if you go around claiming that you appreciate it at some higher level, and can in even tell the difference between minutely different varieties of it, you can appear refined and sophisticated to the naive who have not yet learned to pretend to like it.
Chocolate used to be about tasting good: In this regard milk chocolate is obviously superior. Now all sorts of people turn their nose up at milk chocolate and sniff that they only consume fine dark chocolate. No less than 80% cocoa please. If you ask why they would want to eat that bitter crap suitable only for baking or mixing with milk to make an edible confection, they start talking about fruity aromas and what year the cocoa beans were harvested. Get the picture? They are chocolate snobs who, exactly like wine snobs, actually don't much like the stuff either, but prefer artificial superiority to genuine enjoyment.
It's a sad day when this attitude infects even Hershey's, long the bastion of low-brow but good-tasting milk chocolate. How long will it be before there are whole stored dedicated to inedible dark chocolate sorted by vintage, while those seeking the simple pleasure of good chocolate have to turn to the back isles of the grocery store, next to the grape juice?Source:Grocery StoreContributor:Theodore GrayAcquired:8 March, 2008Text Updated:8 March, 2008Price: $4Size: 4"Composition:CHO

Cicada killer.
Another bug donated by my assistant Nick. Look at the size of the stinger on that thing! I'm not much of a bug expert but my understanding is that these things kill and eat cicadas: I'm not sure what happens if they turn on you.Source:Nick MannContributor:Nick MannAcquired:27 October, 2007Text Updated:27 September, 2008Price: DonatedSize: 1"Composition:C(H2O)

Jet Lignite.
Description from the source:
Lignite var. Jet (Gagate, Giaietto), Ucraina. In reality not a mineral, but a significative example for the C, with a value because used in gemmology. 3,1x2x2 cm; 4 g.Source:Simone CitonContributor:John GrayAcquired:26 September, 2008Text Updated:28 September, 2008Price: TradeSize: 1.25"Composition:C

Soda-lime glass Medallion.
I made this medallion for an article in my Popular Science column, using a charcoal grill to melt the ingredients (silica sand, washing soda and limestone) together into soda-lime glass. Once melted I pressed the glass (darkened by ashes from the fire) into a graphite mold I had machined and heated in the fire.Source:Theodore GrayContributor:Theodore GrayAcquired:26 October, 2008Text Updated:26 October, 2008Price: $1Size: 2.5"Composition:SiO2+Na2CO3+CaCO3

3D Lenticular Periodic Table Puzzle.
In late 2006 I published a photo periodic table and it's been selling well enough to encourage me to make new products. This is a 3D lenticular (stereo image) periodic table that's been cut up into puzzle pieces and put into a really nice glossy box. I have to admit it's not my favorite periodic table product: The pieces are a little hard to put together. But people seem to like it. Check out my poster page to read about (and buy!) the puzzle and other periodic table products.Source:Theodore GrayContributor:Theodore GrayAcquired:19 November, 2008Text Updated:20 November, 2008Price: $25Size: 5"Composition:CHO

Burned Barbie doll (with glasses).
This Barbie (TM) brand doll head is meant for kids to practice hair dressing on: It's about 3/4 life size. Unfortunately this Barbie decided to play with fireworks and had a bad day. Fortunately, she was wearing her safety glasses, and while she may spend some time in the hospital, she's going to be fine, her eyes intact and undamaged.
You don't have to imagine what her fate would have been if she'd failed to ware safety glasses, just check out the next sample.Source:WalmartContributor:Theodore GrayAcquired:8 February, 2009Text Updated:8 February, 2009Price: $40Size: 12"Composition:CHO

Burned Barbie doll (no glasses).
This Barbie (TM) brand doll head was very foolish. She, like her sister featured in the previous sample, had a bad day playing with fireworks. But unlike her sister, she failed to ware safety glasses and as a result will now spend the rest of her life blind in both eyes.
Everyone learn from foolish Barbie: WEAR SAFETY GLASSES when working with dangerous chemicals, especially if there is a team making a safety video in the area.Source:WalmartContributor:Theodore GrayAcquired:8 February, 2009Text Updated:8 February, 2009Price: $40Size: 12"Composition:CHO

Chrome Vanadium Wrench.
Many tools are made of chrome-vanadium steel, an alloy that is tough, hard and not too expensive. Typical alloys contain about 1% chromium and a few tenths of a percent of vanadium.Source:Hardware StoreContributor:Theodore GrayAcquired:28 February, 2009Text Updated:1 March, 2009Price: $8Size: 8"Composition:FeCCrV

Halothane vaporizer.
Halothane is C2HBrClF3, basically a chlorofluorocarbon of the ozone-depleting variety. But surprisingly, it's also a very widely used surgical anesthetic. This vaporizer is used for administering the gas to patients and has controls for carefully adjusting the dose.Source:eBay seller i_sell_techContributor:Theodore GrayAcquired:28 February, 2009Text Updated:1 March, 2009Price: $100Size: 8"Composition:C2HBrClF3

Pretty seashell.
This pretty example of calcium carbonate was made by some kind of seashell making sea creature and washed up on a beach in Florida, I think.Source: FloridaContributor:Theodore GrayAcquired:28 February, 2009Text Updated:1 March, 2009Price: DonatedSize: 2"Composition:CaCO3

Coral.
Very beautiful and rare Hawaiian coral, traded for a poster and some nickel and copper nodules. This is the information that came with it:

Hawaiian Precious 'Pink Beauty' Coral

Precious coral has been for centuries prized by the people in Japan-third in value after gold and silver-because of its fine dense quality, its exquisite colors, and because it always has been associated with 'good luck,' and for several hundred years, expert craftsmen in several coral centers of Japan have been fashioning such precious coral of various shades and colors into fine pieces of jewelry-ornaments for Obi Clasps, kanzashi (ornamental hair pins), and more recently into rings, pendants, necklaces, and brooches This precious coral is completely different from black coral. Whereas black coral is merely an organic compound, precious coral is a calcium carbonate crystal commonly known as calcite, and is composed of hard skeletons of certain marine organism and grows very slowly, possibly at a rate of approximately one inch every 200 years, and in Hawaii occurs in colors from a salmon red, dark pink, pink, pale pink to snow white. 'Angel Skin' is the term commonly applied to the dark pink and medium pink shades.

The precious coral you have in your hand is a representation from only several hundred pounds of which were harvested from a depth of 1200 to 1500 feet (the length of 4 to 5 football fields) in the Molokai Channel, only a 'stones throw' from the Makapuu Lighthouse on the island of Oahu and is therefore genuinely Hawwaiin. The 'ground' which was discovered by University of Hawaii scientists in the fall of 1966 is so far the only known production area in the island chain, and several attempts to locate other grounds in the waters of the Hawaiian Islands have been unsuccessful. Precious Coral-the prefect gift and souvenir of Hawaii-from Hawaii-buff it, polish it, fashion it into jewelry of your own design, or just save it as a memento of your prefect Hawaii vacation.

Crude Oil.
Very hard to get considering how much of the stuff trades hands every day. Just try to buy less than a shipload of it. This is semi-sweet crude from the Frontier Formation in Riverton, Wyoming, and dates to the late Cretaceous, about 65 million years ago. The "sweetness" of crude refers to its sulfur content: The "light sweet crude" you hear about on the news whenever its price is particularly extreme is low-sulfur, low-viscosity crude considered particularly disarable for refining into gasoline.
It actually does taste sweet, I'm told by people who probably haven't tasted it either.Source:eBay seller quartzpegmatiteContributor:Theodore GrayAcquired:11 March, 2009Text Updated:13 March, 2009Price: DonatedSize: 1"Composition:CH2

Chrome Vanadium Wrench.
Many tools are made of chrome-vanadium steel, an alloy that is tough, hard and not too expensive. Typical alloys contain about 1% chromium and a few tenths of a percent of vanadium.Source:Hardware StoreContributor:Theodore GrayAcquired:28 February, 2009Text Updated:1 March, 2009Price: $8Size: 8"Composition:FeCCrV

Dragonfly.
Another in the line of dead insects supplied by my assistant Nick, behold this magnificent dragonfly. As with the previous fly and cicada killer contributions, all these insects died a natural death: No bugs were harmed in the creation of this website.Source:Nick MannContributor:Nick MannAcquired:13 June, 2009Text Updated:14 June, 2009Price: DonatedSize: 3"Composition:C(H2O)

Davy Lamp.
An antique "Davy lamp", named after Sir Humphry Davy and used by miners before the invention of electric lights. The wire mesh, against all odds, prevents the flame from igniting flammable gases surrounding the lamp in a mine.Source:eBay seller curiodream100Contributor:Theodore GrayAcquired:13 January, 2010Text Updated:13 January, 2010Price: $50Size: 10"Composition:CuZnCH

Carbon, Illinois. (External Sample)
Something makes me think this tower is seriously mislabeled: I bet there is very little carbon in there. In case you miss the water tower, they have a sign on the road too:Location:Carbon, IllinoisPhotographed:22 November, 2003Size: 5 milesPurity: 0%

Real diamond. (External Sample)
According to the data sheet, this diamond is 6.5mm in diameter, weighs 1.05 carets, and is VS2 clarity, G color. Apparently that makes it worth $14,000, or at least that's the size of the check I had to leave with the very kind and helpful jeweler when I borrowed it for an afternoon. I admit it is rather nice, but is it really 10,000 times nicer than a 10mm cubic zirconia, which costs about $1.40? Personally, for that kind of money, I think I'd rather have my sparklies by the bucket full. (Actually, that's not a fair comparison because $1.40 is a wholesale price. But it's a lot easier to buy CZ at wholesale prices than it is to buy a diamond that way, or even find out what the wholesale price of the diamond is. The diamond trade knows very well that their livelihood depends on keeping prices artificially high, so they protect their margins fiercely.)

The main difference I can see is that the real diamond shows more flashes of color, and of course it's harder. If you see dust on the surface, it's not for lack of trying. After getting prior approval from the jeweler, I cleaned it with Windex, steam, and alcohol. It got better, but when things are that small and that brightly illuminated, it's really hard to keep dust from settling back on them during the course of photography (which takes half an hour in my 360-degree rotational setup).

After this trashing of the value of diamonds, I would like to thank Christopher and Nate at Christopher's Fine Jewelry in Champaign, Illinois for letting me borrow this very fine diamond. I'm sure if money is no object, it would be a very nice thing to keep locked up in a safe deposit box where you never get to see it.

I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of..